The objective of this research is to develop practical and efficient syntheses of benzophenanthridine, protoberberine, spirobenzylisoquinoline, yohimbane, and indeno(l,2-c)isoquinoline alkaloids. A new beta-lactam antibiotic synthesis is also proposed. Specific targets have been selected in view of either the demonstrated or the potential antileukemic activities of certain members of these classes. The approach is largely based upon recently discovered or projected chemistry involving: (1) the condensation of Schiff bases with homophthalic anhydrides; (2) the reactions of imines with diketene and malonic anhydride; (3) the oxidizing ability of thionyl chloride. Whenever possible our strategy has been to utilize convergent as opposed to linear sequences and to synthesize key intermediates within each class which are designed to allow their facile conversion to a variety of structurally related natural products. The resulting compounds should be of value in the elucidation of pharmacological structure-activity relationships. Certain aspects of the conformations, DNA binding parameters, in vitro cytotoxicities, and in vivo antitumor activities of these compounds will be investigated and the results of these studies will be applied to the design of new potential antitumor agents.